1. Field of the Invention
The present invention relates generally to Behind-the-Ear (BTE) devices that wirelessly communicate with implantable hearing aid system prostheses, and more particularly to a radio frequency antenna for a BTE device.
2. Related Art
Implantable hearing prostheses, such as cochlear implants, typically include an internal portion with a receiver and electrical stimulator secured in bone beneath the skin, and an external BTE device with a microphone, speech processor and an antenna.
The antenna is used for communicating processed sound information over a radio frequency link to the implant, communication with a remote control device for the hearing aid or implant, or in some cases for bilateral communication between two or more BTE devices. The radio frequency antenna is also used to provide a convenient transcutaneous link.
Typically, the radio frequency antenna is implemented entirely inside the body of the BTE device, with much effort taken to optimise the antenna efficiencies so as to improve the wireless link performance and range. As a consequence, however, the size of the BTE devices are governed by the size of antenna implemented within the body of the BTE.
It is desirable for BTE devices to be smaller and as a consequence, the current trend is for some BTE devices to be constructed with a part of the antenna implementation inside earhook portions of the BTE device. However, these earhook antennas are often connected to the antenna connector on the BTE device using an inefficient and unreliable electrical galvanic connection, particularly in higher radio frequency ranges.
U.S. Pat. No. 6,748,094 to Advanced Bionics Corporation discloses a connector system for detachably connecting earhooks to a BTE device, based upon galvanic connections between the earhook and BTE device.